LOL, you will get as many answers as there are quilters and you know what? There is NO universal answer. It entirely depends on preference and application.
How much do you want the thread to show? Do you want it to play a prominent role or just add texture to your quilt?
Do you do alot of detailed machine quilting like Diane Gaudinski and not want heavy build up? Then you should be using a very fine thread like silk, invisafil, bottom line or so fine
Do you want the thread to be heavier and show more? Maybe be a little shiny and pop? Then perhaps an embroidery thread like Isacord, Filtec Glide or Superior Highlights would be the better choice.
Maybe you are a purest and ONLY want cotton thread, YLI, Superior threads, connecting threads and filtec all make wonderful cotton threads for FMQ.
Have a quilt where only a variegated will give you what you want? Turn to King Tut or Rainbows by Superior.
My quilt needs bling!! Go wild with a metallic. Superior threads, YLI and Fil tec all have an offering in metallics.
So you see, there is no universal type or brand for FMQ.